Regulator valve

ABSTRACT

A regulator valve is structured such that hydraulic pressure to be output from a regulated pressure output port is regulated according to urging forces, i.e., line pressure to be regulated, throttle pressure, spring force from a compression coil spring, and operating force from a plunger, which are applied to a valve spool. The plunger has a small diameter portion and a large diameter portion having a diameter larger than the diameter of the small diameter portion, both of which are axially displaceably retained in a spring receiving sleeve. The small diameter portion is urged in one axial direction at one end of the plunger that protrudes into a spring chamber and faces the valve spool, while the large diameter portion is urged in the other axial direction by range pressure at the other end of the plunger which is isolated from the small diameter portion located in the spring chamber.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a regulator valve provided in a hydrauliccontrol apparatus of an automatic transmission. More particularly, theinvention relates to a regulator valve suitable for use as a primaryregulator valve that controls line pressure.

2. Description of the Related Art

A hydraulic control apparatus that controls a vehicular automatictransmission is provided with a plurality of valves in a valve bodymounted to a shift mechanism. This hydraulic control apparatus controlsa plurality of friction apply elements in the transmission by regulatingthe hydraulic pressure and switching the supply and discharge path ofhydraulic fluid discharged from an oil pump, using these valves. One ofthe valves provided is a regulator valve which controls the linepressure which is the base for the apply pressure of the individualfriction apply elements in the automatic transmission. This regulatorvalve is provided to regulate the pressure of the hydraulic fluiddischarged from the oil pump according to the vehicle speed, thethrottle opening amount, and the like.

Typically in this regulator valve, a valve spool that appropriatelyconnects a supply pressure port to which line pressure is supplied witha drain port is urged to one side in the axial direction by linepressure to be regulated being applied from one end, and is urged to theother side in the axial direction by urging force corresponding to acoil spring which is interposed between the valve body and the valvespool at the other end, and throttle pressure that is generatedaccording to engine output.

Japanese Patent No. 3087326, Japanese Patent Application Publication No.2006-153238 (JP-A-2006-153238), and Japanese Patent ApplicationPublication No. 5-99302 (JP-A-5-99302), for example, describe regulatorvalves that regulate the line pressure PL in the following manner. FIG.3 shows a specific example of this type of regulator valve. As shown inFIG. 3, a coil spring 32 and a spring receiving sleeve 34 are providedinside a valve chamber 33 of a valve body 31. This spring receivingsleeve 34 axially displaceably houses a straight plunger 36, one end ofwhich faces a valve spool 35 and the other end of which receives reverserange pressure PL(R). As a result, both throttle pressure PSLT andoperating force corresponding to the reverse range pressure PL(R) fromthe straight plunger 36 are applied to the valve spool 35 when thereverse range is selected.

In addition, Japanese Patent Application Publication No. 5-157174(JP-A-5-157174), for example, describes another such regulator valve, anexample of which is shown in FIG. 4. With this kind of regulator valve,a stepped plunger 46 having two lands 46 a and 46 b with differentdiameters is housed inside a spring receiving portion 44. The largediameter land 46 a is provided on the side of the stepped plunger 46that is closest to a spool 45. Reverse range pressure PL(R) is appliedbetween these two lands 46 a and 46 b, while throttle pressure PSLT isapplied to the back side of the small diameter land 46 b.

Incidentally, reference characters A1 and A2 in FIG. 3 and referencecharacter A1 in FIG. 4 denote the land portion pressure receiving areasof both ends of each of the valve spools 35 and 45, respectively.Similarly, reference character A3 in FIG. 3 and reference characters A3and A4 in FIG. 4 denote the land portion pressure receiving areas ofboth ends of each of the plungers 36 and 46, respectively.

Also, Japanese Patent Application Publication No. 9-79361(JP-A-9-79361), for example, describes another regulator valve in whichthrottle pressure is applied between large and small lands of a steppedplunger, while throttle pressure, not reverse range pressure PL(R) isalso applied to the back side of the large diameter land, which is theside of the land farthest from a valve spool for regulating the linepressure.

However, with the regulator valve of the related art such as thatdescribed above, force which acts on the valve spools 35 and 45 butwhich does not appear in a pressure regulating expression, such as flowforce or the like, may cause the line pressure to increase beyond thepressure for which the regulator valve was designed (i.e., beyond thedesigned value). That is, a so-called rising amount may increase.

One effective measure to prevent this is to increase the feedbackeffective pressure receiving area (which corresponds to A1−A3 for thestraight plunger 36 and A1−(A3−A4) for the stepped plunger 46, forexample). However, if the pressure receiving area A3 of the plungers 36and 46 of the related art is reduced, the gain of the throttle pressurePSLT will also simultaneously decrease. As a result, the necessaryconditions for regulating the line pressure will no longer be satisfied.

That is, with a straight plunger such as the plunger 36, if the pressurereceiving area A3 of the plunger 36 is reduced, the valve gain of thethrottle pressure PSLT will decrease, and as a result, the necessaryline pressure when the throttle is fully open will not be able to beachieved.

Also, with the stepped plunger of the related art, the plunger moveseven in the drive range so the only way to increase the feedbackeffective pressure receiving area without changing the pressurereceiving area A3 which affects the drive range pressure setting is toincrease the pressure receiving area A4. As a result, however, the gainof the throttle pressure decreases such that the necessary line pressurewhen the throttle is fully open is unable to be achieved. Furthermore,because the plunger 46 moves even in the drive range, the stability ofthe hydraulic control may decline. In addition, the plunger 46 is noteasy to be assembled.

Moreover, with both of the regulator valves of the related art, thedecrease in the gain of the throttle pressure can be compensated for byincreasing the throttle pressure receiving area on the valve spool 35and 45 side. Doing this, however, would increase the size of the valve,which means that the valve would require more mounting space.

For these reasons, it is difficult for the regulator valves of therelated art to ensure both feedback effective pressure receiving areaand the necessary line pressure, while fitting into a limited space.

SUMMARY OF THE INVENTION

This invention thus provides a regulator valve capable of ensuring bothfeedback effective pressure receiving area and the necessary linepressure, while fitting into a limited valve mounting space.

(1) A first aspect of the invention relates to a regulator valve whichconstitutes a portion of a hydraulic control apparatus of an automatictransmission. This regulator valve includes a valve body having a valvechamber and a plurality of ports; a valve spool which is axiallydisplaceably housed in the valve chamber; a coil spring which is housedin the valve chamber in such a manner as to be interposed between thevalve body and the valve spool; and a plunger which is displaceablyhoused in the valve body, a first end side of the plunger defining aspring chamber that houses the coil spring between the plunger and thevalve spool, and a second end side of the plunger receiving a rangesignal pressure through one of the plurality of ports. In this regulatorvalve, the hydraulic pressure discharged from one of the plurality ofports is regulated according to the displacement of the valve spool fromthe valve spool being urged to a first side in the axial direction byhydraulic pressure to be regulated that is received through one of theplurality of ports, and being urged to a second side in the axialdirection by a combination of i) throttle pressure from one of the portsthat is connected to the spring chamber, ii) spring force from the coilspring corresponding to the displacement of the valve spool, and iii)operating force of the plunger corresponding to the throttle pressureand the range signal pressure. Moreover, the plunger has a smalldiameter portion and a large diameter portion which has a diameterlarger than the diameter of the small diameter portion, both of whichare axially displaceably retained in the valve body. The small diameterportion is urged to the first side in the axial direction at a first endside which faces the valve spool, and the large diameter portion isurged to the second side in the axial direction by the range signalpressure at a second end side which is isolated from the small diameterportion located in the spring chamber.

According to this structure, the pressure receiving area of the plungerthat receives the range signal pressure and the pressure receiving areao the plunger that receives the throttle pressure can be set separately.Therefore, the feedback effective pressure receiving area for the linepressure can be increased by making the pressure receiving area of thelarge diameter portion of the plunger that receives the range signalpressure smaller than the pressure receiving area of the valve spoolthat receives the feedback line pressure. As a result, the rising amountcan be reduced. Also, the effective pressure receiving area of the smalldiameter portion of the plunger that receives the throttle pressure canbe increased by reducing the pressure receiving area of the smallportion of the plunger that receives the throttle pressure. This makesit possible to ensure the required valve gain of the throttle pressure,and thus ensure the necessary line pressure.

(2) In the regulator valve described in (1) above, the plurality ofports of the valve body may include a feedback pressure port, a supplypressure port, a drain port, and a regulated pressure output port, aswell as a throttle pressure port to which the throttle pressure issupplied, and a range signal pressure port to which the range signalpressure is supplied. Also, the valve spool may be displaced in theaxial direction to selectively connect the supply pressure port with theregulated pressure output port and the drain port by being urged to theone side in the axial direction by the hydraulic pressure to beregulated that is received through the feedback pressure port at a firstend side, and being urged to the second side in the axial direction byreceiving, at a second end side, the combination of i) the throttlepressure inside the spring chamber, ii) the spring force from the coilspring corresponding to the displacement of the valve spool, and iii)the operating force of the plunger corresponding to the throttlepressure and the range signal pressure. Accordingly, the valve structureis simplified.

(3) In the regulator valve described in (2) above, the valve spool mayhave a first land portion that receives the hydraulic pressure to beregulated. Also, a pressure receiving area of the large diameter portionof the plunger that receives the range signal pressure may be smallerthan the pressure receiving area of the first land portion that receivesthe hydraulic pressure to be regulated. This structure increases thefeedback effective pressure receiving area for the line pressure,thereby enabling the rising amount of the hydraulic pressure to beregulated, which is caused by flow force or the like, from decreasing.

(4) Also, in the regulator valve described in (1) to (3) above, thevalve spool may have a second land portion that receives the throttlepressure in the spring chamber. Also, the pressure receiving area of thesmall diameter portion of the plunger that receives the throttlepressure may be smaller than the pressure receiving area of the secondland portion that receives the throttle pressure. This structureincreases the effective pressure receiving area for the throttlepressure, thereby ensuring the gain of the throttle pressure, whichenables the necessary line pressure to be ensured.

(5) The regulator valve described in any one of (1) to (4) above mayalso include a sleeve-shaped spring receiving member that is housedinside the spring chamber in such a manner as to be interposed betweenthe coil spring and the valve body. Moreover, the spring receivingmember may be formed of a first inside diameter portion that axiallydisplaceably retains the small diameter portion of the plunger, and asecond inside diameter portion that axially displaceably supports thelarge diameter portion of the plunger. Further, a drain passage whichopens into a space between the spring receiving member and the plungermay be formed between the first inside diameter portion and the secondinside diameter portion.

In this case, the large diameter portion of the plunger is inside thespring receiving member and the small diameter portion of the plunger isretained by the spring receiving member. As a result, the plunger andthe spring receiving member can be vertically fit into the valve bodywith the plunger already having been fit into the spring receivingmember, which also facilitates automation of the assembly of a hydrauliccontrol apparatus of an automatic transmission.

This aspect of the invention makes it possible to provide a regulatorvalve in which i) a stepped plunger is structured such that the pressurereceiving area of the plunger that receives the reverse range pressureand the pressure receiving area of the plunger that receives thethrottle pressure are able to be set separately, and ii) the pressurereceiving area for the range signal pressure is made smaller than thepressure receiving area of the valve spool that receives the feedbackline pressure, while the pressure receiving area for the throttlepressure is reduced. Accordingly, the rising amount of the hydraulicpressure that is to be regulated can be reduced by increasing thefeedback effective pressure receiving area for the line pressure. Thismakes it possible to ensure the required valve gain of the throttlepressure, which in turn makes it possible to ensure the necessary linepressure. In addition, it is possible to provide a regulator valve thatcan also contribute to automation of the assembly of a hydraulic controlapparatus of an automatic transmission by having the plunger and thespring receiving member able to be vertically fit into the valve bodywith the plunger already having been fit into the spring receivingmember.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and further features and advantages of the invention willbecome apparent from the following description of example embodimentswith reference to the accompanying drawings, wherein like numerals areused to represent like elements and wherein:

FIG. 1 is a sectional view of a body of a regulator valve according to afirst example embodiment of the invention;

FIG. 2 is a block diagram schematically showing a portion of a hydrauliccontrol apparatus that includes a device which supplies hydraulicpressure to the regulator valve of the first example embodiment of theinvention;

FIG. 3 is a sectional view of a body of a regulator valve according to afirst example of related art; and

FIG. 4 is a sectional view of a body of a regulator valve according to asecond example of related art.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, example embodiments of the invention will be described withreference to the accompanying drawings.

FIG. 1 is a sectional view of a body of a regulator valve according to afirst example embodiment of the invention, and shows an example in whichthe invention has been applied to a primary regulator valve thatconstitutes part of a hydraulic control apparatus of a stepped automatictransmission. Also, FIG. 2 is a block diagram schematically showing aportion of the hydraulic control apparatus that includes a device whichsupplies hydraulic pressure to the regulator valve of this exampleembodiment.

First the structure of the regulator valve will be described. As shownin FIG. 1, the regulator valve 10 according to this example embodimentincludes a valve body 11, a valve spool 12, and a compression coilspring 13. The valve body 11 has a cylindrical valve chamber 11 r whichis closed-off at one end and a plurality of ports 11 a, 11 b, 11 c, 11d, 11 e, 11 f, 11 g, and 11 h which are all connected to this valvechamber 11 r. The valve spool 12 is housed in the valve chamber 11 r insuch a manner that it can slide displaceably in the axial direction. Thecompression coil spring 13 is housed inside the valve chamber 11 r in aposition interposed between the valve body 11 and the valve spool 12.

The regulator valve 10 also includes a spring receiving sleeve 14 (i.e.,a sleeve-shaped spring receiving member) and a plunger 15. The springreceiving sleeve 14 is housed inside the valve chamber 11 r in aposition interposed between the compression coil spring 13 and the valvebody 11. The plunger 15 is housed inside the spring receiving sleeve 14in a manner such that it is able to displaceably slide. One end of thisplunger 15 defines a spring chamber 17 which houses the coil spring 13between the plunger 15 and the valve spool 12. The other end of theplunger 15 receives reverse range pressure PL(R) (i.e., range signalpressure) through the port 11 h, from among the plurality of ports 11 ato 11 h.

More specifically, the plurality of ports 11 a to 11 h of the valve body11 include a feedback pressure port 11 a, a supply pressure port 11 d, adrain port 11 c, and a regulated pressure output port 11 e, as well as athrottle pressure port 11 f to which throttle pressure PSLT is supplied,a drain port 11 g, and a reverse range pressure port 11 h to whichreverse range pressure PL(R) is supplied.

The valve spring 12 has a first land portion 12 a which receives linepressure PL, which is the hydraulic pressure to be regulated by theregulator valve 10, through the feedback pressure port 11 a. The valvespool 12 is urged to the tight in FIG. 1 (i.e., to one side in the axialdirection) by pressure corresponding to the line pressure PL that is fedback and the pressure receiving area A1 of the first land portion 12 athat receives that line pressure PL.

Further, the valve spool 12 has a second land portion 12 d that receivesthrottle pressure PSLT, which will be described later, which is suppliedinto the spring chamber 17. One end of the compression coil spring 13 isengaged with this second land portion 12 d. As a result, the valve spool12 is urged to the left in FIG. 1 (i.e., to the other side in the axialdirection) by a combination of i) the pressure corresponding to thethrottle pressure PSLT and the pressure receiving area A2 of the secondland portion 12 d that receives that throttle pressure PSLT, ii) springforce (acting to the left in FIG. 1) from the compression coil spring 13corresponding to the displacement of the valve spool 12 (hereinafter,this spring force may also be referred to as “Fsp”), and iii) theoperating force of the plunger 15 that receives the throttle pressurePSLT and the reverse range pressure PL(R).

The valve spool 12 thus regulates the hydraulic pressure to be outputfrom the regulated pressure output port 11 e by being axially displacedaccording to these urging forces to one side and the other side in theaxial direction, so as to selectively connect the supply pressure port11 d with the regulated pressure output port 11 e or the drain port 11c.

Meanwhile, the plunger 15 is formed of a small diameter portion 15 a anda large diameter portion 15 b that has a larger diameter than thediameter of the small diameter portion 15 a. Both the small diameterportion 15 a and the large diameter portion 15 b are retained by thespring receiving sleeve 14 in a manner such that they are slidinglydisplaceable in the axial direction. The small diameter portion 15 a isurged to one side (i.e., the right side in FIG. 1) in the axialdirection at one end (i.e., the left end in FIG. 1) of the plunger 15that protrudes into the spring chamber 17 and faces one end portion 12 eof the valve spool 12. The large diameter portion 15 b is urged to theother side (i.e., the left side in FIG. 1) in the axial direction byreverse range pressure PL(R) from the reverse range pressure port 11 hat the other end (i.e., the right end in FIG. 1) of the plunger 15 whichis isolated from the small diameter portion 15 a located in the springchamber 17.

Here, the pressure receiving area A3 of the large diameter portion 15 bof the plunger 15 that receives the reverse range pressure PL(R) is madeto be comparatively smaller than the pressure receiving area A1 of thefirst land portion 12 a of the valve spool 12 that receives the feedbackline pressure PL.

Also, the pressure receiving area A4 of the small diameter portion 15 aof the plunger 15 that receives the throttle pressure PSLT is made to becomparatively smaller than the pressure receiving area A2 of the secondland portion 12 d of the valve spool 12 that receives the throttlepressure PSLT.

Furthermore, the pressure receiving area A2 of the second land portion12 d of the valve spool 12 that receives the throttle pressure PSLT ismade to be larger than the pressure receiving area A1 of the first landportion 12 a of the valve spool 12 that receives the feedback linepressure PL. That is, the pressure receiving area A3 of the largediameter portion 15 b of the plunger 15 that receives the reverse rangepressure PL(R) is larger than the pressure receiving area A4 of thesmall diameter portion 15 a of the plunger 15 that receives the throttlepressure PSLT but smaller than the pressure receiving area A1 of thefirst land portion 12 a of the valve spool 12 that receives the feedbackline pressure PL. Hence, the relationship in size among the pressurereceiving areas A1 to A4 is A2 >A1 >A3 >A4.

The valve spool 12 also has intermediate land portions 12 b and 12 c.The land portion 12 c connects the supply pressure port 11 d with thedrain port 11 e when the valve spool 12 moves a predetermined amount tothe right in FIG. 1.

Meanwhile, the spring receiving sleeve 14 is a stepped cylinder which isclosed-off at one end, formed of a first inside diameter portion 14 aand a second inside diameter portion 14 b. The first inside diameterportion 14 a axially displaceably retains the small diameter portion 15a of the plunger 15, while the second inside diameter portion 14 baxially displaceably supports the large diameter portion 15 b of theplunger 15. Also, between the first inside diameter portion 14 a and thesecond inside diameter portion 14 b of the spring receiving sleeve 14 isformed a drain passage 14 c that opens into an annular space 16 betweenthe spring receiving sleeve 14 and the plunger 15. Moreover, a notchportion 14 d cut out to the right in FIG. 1 is formed in the rear end ofthe second inside diameter portion 14 b of the spring receiving sleeve14. The open end side of the spring receiving sleeve 14 is sealed sothat it is liquid tight by a plug 18 having a protrusion 18 a that fitsinto this notch portion 14 d. Then the spring receiving sleeve 14 andthe plug 18 are integrally fixed to the valve body 11 so that they willnot slip out by a retaining pin 19 that passes through the valve body 11and the spring receiving sleeve 14 and sticks into the plug 18 in adirection perpendicular to their axes.

As shown in FIG. 2, the line pressure PL which serves as the feedbackpressure is the pressure at which hydraulic fluid discharged from theoil pump 20 provided in the automatic transmission is supplied to thefeedback pressure port 11 a via an orifice 21 a and an orifice which isnot shown but is provided upstream of that orifice 21 a. Also, thethrottle pressure PSLT is regulated to a pressure corresponding to theengine output torque by a throttle pressure regulating device 23 whichincludes a linear solenoid valve 22, for example, and then supplied tothe throttle pressure port 11 f. Moreover, the reverse range pressurePL(R) is supplied from a manual valve 24 when the reverse range (R) isselected, according to the switching position of the manual valve 24which operates in response to a range selection operation by a driver.Also, output pressure that is output from the regulated pressure outputport 11 e is supplied to a secondary regulator valve 25 where converterpressure and lubrication oil pressure suitable for the vehicle speed andengine output are further regulated based on the throttle pressure PSLT.Incidentally, when the forward range (see ranges D, 1 and 2 of themanual valve 24 in FIG. 2) is selected, hydraulic pressure is suppliedand discharged via shift valves and an accumulator and the like, none ofwhich are shown, to operate friction apply elements corresponding to theappropriate gears. This is well known and so will not be described indetail here.

Next, assembly of the regulator valve according to this exampleembodiment will be described.

First, the stepped plunger 15 is inserted into the spring receivingsleeve 14 from the small diameter portion 15 a side. Then the protrusion18 a of the plug 18 is fit into the notch portion 14 d of the springreceiving sleeve 14 such that the open end side of the spring receivingsleeve 14 is sealed off by the plug 18.

Meanwhile, the valve spool 12 is inserted into the valve chamber 11 r ofthe valve body 11 that has been oriented upright with a jig or the likefor assembly. Then the compression coil spring 13 is inserted lengthwiseinto the valve chamber 11 r of the valve body 11.

Next, an assembly of the spring receiving sleeve 14 which houses theplunger 15 and which has been sealed by the plug 18 is set into thevalve body 11 with the small diameter portion 15 a of the plunger 15facing downward.

At this time, the assembly of the spring receiving sleeve 14 is fit intothe valve chamber 11 r of the valve body 11 while compressing thecompression coil spring 13 that is already housed in the valve chamber11 r. Also, the spring receiving sleeve 14 is roughly positioned in apredetermined position in the rotational direction with respect to thevalve body 11 by the notch portion 14 d of the spring receiving sleeve14 and the protrusion 18 a of the plug 18.

Next, the spring receiving sleeve 14 and the plug 18 are integrallyfixed to the valve body 11 so as not to slip out by inserting theretaining pin 19 through the valve body 11 and the spring receivingsleeve 14 and into a notch portion of the plug 18.

Next, the operation of the regulator valve will be described.

With a hydraulic control apparatus of an automatic transmission providedwith a regulator valve such as the regulator valve 10 described above,when the engine speed increases in the forward range, and as a result,the speed of the oil pump 20 increases, for example, the line pressurePL increases, and as it does so, it tries to push the valve spool 12 tothe right in FIG. 1. However, as the engine output increases, so toodoes the throttle pressure, which tries to push the valve spool 12 tothe left in FIG. 1, thus enabling the displacement amount of the valvespool 12 to be appropriately adjusted. Incidentally, at this timereverse range pressure PL(R) is not supplied so the plunger 15 is keptin the rightmost position by the throttle pressure PSLT.

On the other hand, when the reverse range is selected by a rangeswitching operation, reverse range pressure PL(R) is supplied from themanual valve 24. Incidentally, the reverse range pressure is the linepressure PL that is supplied via the manual valve 24, as shown in FIG.2.

At this time, the reverse range pressure PL(R) is applied to the largediameter portion 15 b of the plunger 15, causing the plunger 15 to moveto the left. As a result, not only the throttle pressure PSLT but alsothe operating force of the plunger 15 acts on the valve spool 12. Inthis state, the line pressure PL when the reverse range is selected isregulated.

The pressure regulating expression for the reverse range of theregulator valve 10 in this state can be expressed by Expression (1)below.

$\begin{matrix}{{PL} = {{\frac{{A\; 2} - {A\; 4}}{{A\; 1} - {A\; 3}}{PSLT}} + \frac{Fsp}{{A\; 1} - {A\; 3}}}} & (1)\end{matrix}$

where A1 is the pressure receiving area of the valve spool that receivesfeedback pressure; A2 is the pressure receiving area of the valve spoolthat receives throttle pressure; A3 is the pressure receiving area ofthe plunger that receives reverse range pressure; A4 is the pressurereceiving area of the plunger that receives throttle pressure; and Fspis the spring force of the compression coil spring.

In this example embodiment, the pressure receiving area A3 of thestepped plunger 15 that receives the reverse range pressure PL(R) andthe pressure receiving area A4 of the stepped plunger 15 that receivesthe throttle pressure PSLT can be set separately, so the pressurereceiving area A3 of the stepped plunger 15 that receives the reverserange pressure PL(R) is made comparatively smaller than the pressurereceiving area A1 of the valve spool 12 that receives the feedback linepressure PL, while the effective pressure receiving area (A2−A4) isincreased. Therefore, the feedback effective pressure receiving area(A1−A3) for the line pressure PL in Expression (1) above can beincreased so even if flow force Ff that is not expressed in the pressureregulating expression is generated at the regulated pressure output port11 e or the like, the effect corresponding to Ff/(A1−A3) can besuppressed which enables the rising amount of the line pressure to bereduced.

Also, the diameter of the small diameter portion 15 a of the plunger 15is reduced such that the effective pressure receiving area (A2−A4) forthe throttle pressure PSLT is made larger. As a result, a decrease inthe gain of the throttle pressure PSLT can be prevented, making itpossible to ensure the necessary line pressure at times such as when thethrottle is fully open.

Furthermore, the large diameter portion 15 b of the plunger 15 is insidethe spring receiving sleeve 14 and the small diameter portion 15 a ofthe plunger 15 is retained by the spring receiving sleeve 14. That is,the inside diameter of the first inside diameter portion 14 a of thespring receiving sleeve 14 is smaller than the inside diameter of thelarge diameter portion 15 b of the plunger 15, so the plunger 15 and thespring receiving portion 14 can be fit vertically into the valve body 11with the plunger 15 already having been fit into the spring receivingportion 14. This facilitates automation of the assembly of a hydrauliccontrol apparatus of an automatic transmission. That is, with thestraight spool of the related art, or the stepped plunger of the relatedart in which the valve spool side has a large diameter, it is necessaryto prevent the plunger from slipping out of the spring receiving sleeve.With the regulator valve 10 according to this example embodiment,however, this will not happen so there is no need to prevent it.

Also, with this example embodiment, the feedback pressure is applied toone end of the valve spool 12, while the throttle pressure, the springforce from the compression coil spring 13, and the operating force ofthe plunger 15 are applied to the other end of the valve spool 12, sothe structure is simplified.

In this way, according to the regulator valve of this exampleembodiment, the stepped plunger is structured such that the pressurereceiving area A3 of the plunger 15 that receives the reverse rangepressure PL(R) and the pressure receiving area A4 of the plunger 15 thatreceives the throttle pressure PSLT are able to be set separately, sothe pressure receiving area A3 of the plunger 15 that receives thereverse range pressure PL(R) is made smaller than the pressure receivingarea A1 of the valve spool 12 that receives the feedback line pressurePL, while the effective pressure receiving area (A2−A4) for the throttlepressure PSLT is increased. Therefore, the rising amount of thehydraulic pressure that is to be regulated can be reduced by increasingthe feedback effective pressure receiving area (A1−A3) for the linepressure. This makes it possible to prevent the gain of the throttlepressure PSLT from decreasing, which in turn makes it possible to ensurethe necessary line pressure. As a result, both the feedback effectivepressure receiving area (A1−A3) and the necessary line pressure can beensured within a limited valve mounting space. In addition, it ispossible to provide a regulator valve that can contribute to theautomation of the assembly of a hydraulic control apparatus of anautomatic transmission by having the plunger and the spring receivingsleeve 14 able to be vertically fit into the valve body 11 with theplunger already having been fit into the spring receiving sleeve 14.Incidentally, in the foregoing example embodiment, the range pressuresignal is for the reverse range pressure, but it is not limited to this.That is, the range pressure signal may be a signal for another rangepressure instead.

As described above, the invention is able to provide a regulator valvewhich enables the rising amount of hydraulic pressure to be regulated tobe reduced by increasing the feedback effective pressure receiving areaof the line pressure, thereby preventing the gain of the throttlepressure from decreasing so that the necessary line pressure can beensured. Thus, the invention can provide a regulator valve that canensure both the feedback effective pressure receiving area and thenecessary line pressure while fitting within a limited valve mountingspace. Therefore, the invention is useful for a regulator valve providedin a hydraulic control apparatus of an automatic transmission,particularly a regulator valve in general which is suitable for use as aprimary regulator valve that controls line pressure.

While the invention has been described with reference to exampleembodiments thereof, it is to be understood that the invention is notlimited to the example embodiments or constructions. To the contrary,the invention is intended to cover various modifications and equivalentarrangements. In addition, while the various elements of the exampleembodiments are shown in various combinations and configurations, whichare exemplary, other combinations and configurations, including more,less or only a single element, are also within the spirit and scope ofthe invention.

1. A regulator valve which constitutes a portion of a hydraulic controlapparatus of an automatic transmission, comprising: a valve body havinga valve chamber and a plurality of ports; a valve spool which is axiallydisplaceably housed in the valve chamber; a coil spring which is housedin the valve chamber in such a manner as to be interposed between thevalve body and the valve spool; and a plunger which is displaceablyhoused in the valve body, a first end side of the plunger defining aspring chamber that houses the coil spring between the plunger and thevalve spool, and a second end side of the plunger receiving a rangesignal pressure through one of the plurality of ports, wherein thehydraulic pressure discharged from one of the plurality of ports isregulated according to the displacement of the valve spool being urgedto a first side in the axial direction by hydraulic pressure to beregulated that is received through another of the plurality of ports,and being urged to a second side in the axial direction by a combinationof i) throttle pressure from one of the ports that is connected to thespring chamber, ii) spring force from the coil spring corresponding tothe displacement of the valve spool, and iii) operating force of theplunger corresponding to the throttle pressure and the range signalpressure, and wherein the plunger has a small diameter portion and alarge diameter portion which has a diameter larger than a diameter ofthe small diameter portion, both of which are axially displaceablyretained in the valve body, the small diameter portion is urged to thefirst side in the axial direction at a first end side which faces thevalve spool, and the large diameter portion is urged to the second sidein the axial direction by the range signal pressure at a second end sidewhich is isolated from the small diameter portion located in the springchamber.
 2. The regulator valve according to claim 1, wherein: theplurality of ports of the valve body include a feedback pressure port, asupply pressure port, a drain port, and a regulated pressure outputport, as well as a throttle pressure port to which the throttle pressureis supplied, and a range signal pressure port to which the range signalpressure is supplied; and the valve spool is displaced in the axialdirection to selectively connect the supply pressure port with theregulated pressure output port or the drain port by being urged to theone side in the axial direction by the hydraulic pressure to beregulated that is received through the feedback pressure port at a firstend side, and being urged to the second side in the axial direction byreceiving, at a second end side, the combination of i) the throttlepressure inside the spring chamber, ii) the spring force from the coilspring corresponding to the displacement of the valve spool, and iii)the operating force of the plunger corresponding to the throttlepressure and the range signal pressure.
 3. The regulator valve accordingto claim 1, wherein: the valve spool has a first land portion thatreceives the hydraulic pressure to be regulated; and a pressurereceiving area of the large diameter portion of the plunger thatreceives the range signal pressure is smaller than a pressure receivingarea of the first land portion that receives the hydraulic pressure tobe regulated.
 4. The regulator valve according to claim 1, wherein: thevalve spool has a second land portion that receives the throttlepressure in the spring chamber; and a pressure receiving area of thesmall diameter portion of the plunger that receives the throttlepressure is smaller than a pressure receiving area of the second landportion that receives the throttle pressure.
 5. The regulator valveaccording to claim 1, wherein: the valve spool has a first land portionthat receives the hydraulic pressure to be regulated; the valve spoolhas a second land portion that receives the throttle pressure in thespring chamber; and a pressure receiving area of the second land portionthat receives the throttle pressure is larger than a pressure receivingarea of the first land portion that receives the hydraulic pressure tobe regulated.
 6. The regulator valve according to claim 1, wherein: thevalve spool has a first land portion that receives the hydraulicpressure to be regulated; a pressure receiving area of the largediameter portion of the plunger that receives the range signal pressureis smaller than a pressure receiving area of the first land portion thatreceives the hydraulic pressure to be regulated; the valve spool has asecond land portion that receives the throttle pressure in the springchamber; a pressure receiving area of the small diameter portion of theplunger that receives the throttle pressure is smaller than a pressurereceiving area of the second land portion that receives the throttlepressure; and the pressure receiving area of the second land portionthat receives the throttle pressure is larger than the pressurereceiving area of the first land portion that receives the hydraulicpressure to be regulated.
 7. The regulator valve according to claim 1,further comprising: a sleeve-shaped spring receiving member that ishoused inside the spring chamber in such a manner as to be interposedbetween the coil spring and the valve body, wherein the spring receivingmember is formed of a first inside diameter portion that axiallydisplaceably retains the small diameter portion of the plunger, and asecond inside diameter portion that axially displaceably supports thelarge diameter portion of the plunger; and wherein a drain passage whichopens into a space between the spring receiving member and the plungeris formed between the first inside diameter portion and the secondinside diameter portion.
 8. The regulator valve according to claim 7,wherein a diameter of the first inside diameter portion is smaller thanthe diameter of the large diameter portion.
 9. The regulator valveaccording to claim 1, wherein the range signal pressure is a reverserange signal pressure.
 10. The regulator valve according to claim 3,further comprising: a sleeve-shaped spring receiving member that ishoused inside the spring chamber in such a manner as to be interposedbetween the coil spring and the valve body, wherein the spring receivingmember is formed of a first inside diameter portion that axiallydisplaceably retains the small diameter portion of the plunger, and asecond inside diameter portion that axially displaceably supports thelarge diameter portion of the plunger; and wherein a drain passage whichopens into a space between the spring receiving member and the plungeris formed between the first inside diameter portion and the secondinside diameter portion.
 11. The regulator valve according to claim 4,further comprising: a sleeve-shaped spring receiving member that ishoused inside the spring chamber in such a manner as to be interposedbetween the coil spring and the valve body, wherein the spring receivingmember is formed of a first inside diameter portion that axiallydisplaceably retains the small diameter portion of the plunger, and asecond inside diameter portion that axially displaceably supports thelarge diameter portion of the plunger; and wherein a drain passage whichopens into a space between the spring receiving member and the plungeris formed between the first inside diameter portion and the secondinside diameter portion.
 12. The regulator valve according to claim 5,further comprising: a sleeve-shaped spring receiving member that ishoused inside the spring chamber in such a manner as to be interposedbetween the coil spring and the valve body, wherein the spring receivingmember is formed of a first inside diameter portion that axiallydisplaceably retains the small diameter portion of the plunger, and asecond inside diameter portion that axially displaceably supports thelarge diameter portion of the plunger; and wherein a drain passage whichopens into a space between the spring receiving member and the plungeris formed between the first inside diameter portion and the secondinside diameter portion.